1. Field of the Invention
The present invention relates to a filling element for filling machines, with the filling element having no filling tube and serving for filling bottles, cans, or similar containers with carbonated or non-carbonated liquids. The filling element includes a signal emitter for detecting the designated filling height in a container that is pressed onto the filling element and is to be filled. The signal emitter cooperates with a vertical bore that is disposed in the filling element coaxial to a container seal thereof, and is protected from the entry of liquid from the liquid guidance conduit of the filling element. The signal emitter is part of a measuring device which, when the designated filling height is detected, transmits a signal that triggers closing of the liquid flow valve of the filling element.
2. Description of the Prior Art
Filling elements of the aforementioned general type that have no filling tube are provided with a signal emitter that is responsive to the liquid level that is rising in the pressed-on container to the designated filling height for the purpose of triggering the closure pulse for the liquid flow valve of the filling element. A filling element of this general type is known, for example, from U.S. Pat. No. 4,509,565 Ahlers dated Apr. 9, 1985, which belongs to the assignee of the present application. This filling element is intended for single-chamber and multi-chamber counter pressure filling machines, and includes a signal emitter that is in the form of a switching member and reacts to conductive liquids. This signal emitter is part of a measuring device and is to be introduced into the container that is to be filled as the latter is raised into the filling position. This signal emitter is coaxial to the container seal of the filling element and is vertically and exchangeably inserted into a bore provided in an extension. The extension, which is fixedly provided in the liquid guidance conduit that extends downwardly from the valve seat of the liquid flow valve of the filling element, is provided on its container end with a guide element in the form of a deflector that keeps the liquid that is flowing downwardly in the liquid guidance conduit from the signal emitter as the liquid leaves the liquid guidance conduit. To adjust the filling element to a different designated filling height, for example when the type of container is changed, it is necessary to replace the signal emitter with a different one. Since a filling machine has a number of filling elements, exchanging the signal emitters entails a lot of time and hence leads to a drop in production. A further drawback is that when the signal emitter reacts to the designated filling height, it becomes wetted with liquid, which can lead to bacteriological contamination of the signal emitter.
Another filling element of the aforementioned general type is known from U.S. Pat. No. 3,799,219 uth el al dated Apr. 9, 1974, which also belongs to the assignee of the present application, and has a signal emitter that is disposed within a vertical bore that is centrally disposed in the valve body of the liquid flow valve of the filling element; this signal emitter is to be introduced into a container that is to be filled and that has been placed in a sealed position with the container seal of the filling element. This signal emitter also responds to conductive liquids and, via a lifting mechanism attached to the signal emitter, is lowered from an upper position within the bore of the vlve body to the designated filling height in the container that is in the sealed position. In this position, which is limited by an exchangeable intermediate piece associated with the lifting mechanism, the liquid that is flowing downwardly in the liquid guidance conduit of the filling element is kept from the signal emitter by an extension that is in the form of a guide element and extends downwardly from the sealing element of the valve body. After the signal emitter responds to the liquid that has risen to the designated filling height, the lifting mechanism raises the signal emitter into the upper position. With this filling element, when it is necessary to readjust the latter to a different designated filling height, it is no longer necessary to exchange the signal emitter due to the fact that the latter is adjustable via the lifting mechanism and the intermediate pieces. However, this adjustability represents a considerable capital investment that makes the filling element more expensive. Furthermore, to adjust each filling element to a different designated filling height, the aforementioned adjustability requires exchange of the intermediate piece that limits the lowering movement of the signal emitter.
It is therefore an object of the present invention to improve the filling elements of the aforementioned general type in such a way that it is now possible to eliminate the previously required adjustment, at the filling elements, of the signal emitter to the designated filling height, and hence to eliminate the considerable capital expenditure required for the filling elements, as well as to eliminate the direct response contact of the signal emitter with the liquid with which the respective container has been filled.